Philip lange



(No Model.)

P. LANGE.

GALVANOMETER.

No. 386,992. Patented July 31, 1888.

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UNITED STATES PATENT OFFICE.

PHILIP LANGE, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE VEST- INGHOUSE ELECTRIC COMPANY, OF SAME PLACE.

GALVANOMETER.

SPECIFICATION forming part of Letters Patent No. 386,992, dated July 31, 1888.

Application filed October 29, 1887. Serial No. 253,722.

To all whom it may concern:

Be it known that I, PHILIP LANGE, a subject of the Emperor of Germany, residing in Pittsburg, in the county of Allegheny, in the State of Pennsylvania, have invented certain new and useful Improvements in Electric Meters, of which the following is a specification.

The invention relates to the class of apparatus employed for measuring electric currents;

IO and the object of the invention is to provide convenient and efficient portable apparatus for noting the changes in the current supplied to and traversing an electric circuit, so that it may be readily maintained approximately I 5 constant.

In the accompanying drawings, Figure 1 is a plan of an apparatus orinstrument involving the features of the invention, and Fig. 2 is a cross-section. Fig. 3illustrates certain details.

Referring to the figures, A represents the case for containing the apparatus, and it is provided with a cover, B.

The general plan of the invention is to cause a variation or disturbance in the balance of two branches of a conductor connected across the supply-conductors by means of a variation in the relative resistances caused in two different conducting bodies by the heating effects of electric currents of different electro-motive o forces. The conductor Z Z leads from the binding post h to the binding-post 7L2, being divided into the branches 1 and 2. The connections are preferably made through a switch, S, from a binding-post, h, to the post h. The

branch 1 includes three electric lamps, d (1 d These are, forconvenience, placed in the cover B of the box, which may be thrown back, as

shown in the drawings, when the apparatus is in use.

The lamps are covered by a wiregauze or net-work, c, which prevents them from being broken by accident, or in case they are broken prevents the pieces from falling into the box and injuring the apparatus, at the same time affording sufficient ventilation.

In the box A there is contained a differential coil, 0, wound upon a spool, 0, within which a needle, e, is suspended upon a compass-cap,

6. An armature,f, and a scale, E, are pro- No model.)

vided for this needle. The conductor 1 leads through one of the coils,c,and thelampsdd d. The other branch, 2, includes the remaining coils, c, and includes two artificial resistancecoils, R R, placed in the bottom of the box. These may be covered bya wire-gauze similar to that in the top of the box. The conductor leading from these resistances passes to an adjustable resistance, r, extending along the front portion of the box. A sliding contact,

1", running upon a rod, 1", is employed forde- 6o termining the amount of resistance 1' wh ch shall be inserted. The resistance r consists, preferably, of resistance-wire wound spirally upon a non-conducting rod, 1", and an index,

p, extending above a scale, 19, serves to show the amount of resistance in circuit. The coils O, needle 6, and scale E are carried in a case,

F, which is movable in a rotary direction to adjust the device to act in any desired position with reference to the magnetic poles of the earth.

Itis the design of the invention that when the system is operating with its normal load the current traversing the two branches 1 and 2 shall balance. \Vhen, however, a variation occurs by reason of an increase or decreasein the load in the outside circuit, the change which will occur in the current traversing the lines 1 and 2 will disturb the balance of the resista11ces,and thus more current will traverse the conductor 1 than the conductor 2, or vice versa. The needle 6 will therefore be deflected by reason of the differential action of the coils cc". By then adjusting the supply to the new re quirements of the system the needle will be caused to return to its normal position.

This instrument is especially intended as a portable volt-meter, and it is desired that convenient means be employed for raising the needle eso that it will not be free to swing during transportation. For this purpose a lever, 15, which passes through a bracket, t, and is pivoted upon an axis, 22, passes beneath the needle 6. A set-screw, t pressing upon the lower end of this lever, normally serves to 5 hold it in its required position; but when it is desired to lift the needle the screw may be turned down against the lever t, thereby raising the needle against the upper surface of the aperture in the spool O. I claim as my invention- A portable electric meter consisting of the 5 combination of a divided circuit, one branch containing carbon resistances and the other a metallic resistance, an indicating-needle operated by the currents traversing the two branches a containing-box having a lid in :0 which the carbon-resistances are placed while the metallic resistance is in the other portion of the box, an adjustable resistance in series with said metallic resistance placed in the front of the box, consisting of a coil of wire with a contact movable along its length, anda 15 gauze protection for the carbon resistances, substantially as described.

In testimony whereof I have hereunto subscribed my name this 4th day of November, A. D. 1886.

PHILIP LANGE.

Witnesses:

CHARLES A. TERRY, J. G. BACKOFEN. 

